Telegraph key



July 23, 1963 J. J. JAKOSKY ETAL 3,098,898

TELEGRAPH KEY Filed June 5, 1961 Filed June 5, 1961, Ser. No. 114,959Claims. (Cl. 178-408) This invention relates to an improved dual type oftelegraph key, or electric key mechanism, whose operating lever isactuated in a horizontal plane, to make electrical contact when moved tothe right or left of its center position of rest. The prime object ofthe invention is to provide a keying mechanism which mechanically willhave a definite center-rest position, be positive in its operation andfree of undesirable loose-play.

Another object of the invention is to provide a keying mechanism whichwill make a firm, continuous contact without chatter and contact-bounce.

Another object of the invention is to provide a simple mechanicalarrangement whereby the operating lever is precisely positioned at itscenter position of rest, and at the same time allow independentadjustment to be made of the spring tension controlling the movement toeither the right or left.

Another object of this invention is to provide :a simple mechanicalkeying mechanism for controlling the operation of an automaticelectronic keyer, which latter forms no part of the present invention.

Another object is to provide a key having a base which will providemaximum stability against turning moment, with a minimum overall weight.

Electrically, the key functions as a single pole, double throw switch,whereby electrical contact may be made with either one of two circuits.When connected to an automatic keyer, in the conventional manner, thekeyer will automatically form dashes as long as the lever is held to theleft, and dots as long as it is held to the right. In other words, theobject of this invention is to provide an electric key mechanism, orswitching device, to control an electronic keyer. The keyer thenautomatically forms the dots or dashes, in response to the movement andtiming of the key lever.

Previous keys having definite center-rest positions, have been ofcomplicated mechanical design with one or more of the contact points andrestoring springs positioned on the opposite side of the pivot from thehandle where the actuating side pressures are applied to operate thekey. The inevitable loose-play in the pivot point, therefore, results insloppy mechanical action with resultant poor keying action, especiallyat the higher operating speeds. To overcome this very undesirableaction, the present invention places the restoring spring pressures, thecontact points, and the actuating side pressures, all on the same sideof the pivot or axis of rotation. As a result, the injurious effects ofa loose pivot and complicated mechanical linkages are greatly minimized.

Other important objects of the invention will be apparent upon readingthe following descripiton, together with a study of the drawings showinga preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a general top plan view of the embodiment of the invention.

FIGURE Q is a general side view of the embodiment.

FIGURE 3 is an isometric top view of the moving mechanism, comprisingthe lever and a bifurcated yoke or rocker-arm, and removed from thebase.

The invention is described in the following specifications and drawings;and comprises essentially, a heavy base 1 which rests upon threefrictional rubber feet 2, 2', and 2". A vertical shaft 3 is supported bythe base, and pivoted on this shaft is a lever 4. Pivoted coaxial itStates Patent 3,098,898 Patented July 23, 1963 with the lever is abifurcated yoke or rocker-arm 5 which is pivoted at its bight so it canmove either with or independent of the lever. The yoke 5 brackets lever4 and is normally held against the lever, at bearing point 6, by meansof the compression of a spring 7, which exerts pressure between the leftarm of yoke 5 and the lever 4. The compression of this spring may beadjusted by means of screw 7 and held by lock-nut 7. When at itscenterrest position, the left arm of the yoke is normally held against astop screw 8, having lock-nut 8, by the force exerted by the compressionof a spring positioned between the base and the right arm ofyoke 5. Thecompression in spring 9 may be adjusted by means of the screw 9", havinglock-nut 9".

A contact point 10 is fastened to the yoke, and spaced from a companioncontact point 10' which is fastened to the adjusting screw 11, withlock-nut 11', supported by the post 12. The post -12 is mounted on andelectrically insulated from the base and is connected for conventionaloperationto the dot forming circuit of the keyer. A second contact point13 is fastened to the opposite side of the lever, and is spaced from itscompanion contact point 13' mounted upon the adjusting screw 1-4 withits locknut 14, and supported by the post 15. The post 15 also ismounted on and electrically insulated from the base and normally isconnected to the dash forming circuit of the automatic keyer. Thisdescribes the normal or centerrest position of the mechanism.

An insulated handle or handles, of special mechanical characteristics 16and/or 16', are provided, and electrically insulate the operator fromthe lever. These handles, or paddles, are usually positioned bet-weenthe thumb and the fore-finger of the operating hand. For right-handedoperation, the lever is moved to the right to form dots, by exertingpressure of the thumb against handle 16. Movement of the lever to theleft to form dashes, is obtained by exerting pressure of the fore-fingeragainst the handle 16.

As previously mentioned, the lever and the yoke are suspendedindependent of each other for horizontal movement and in the preferredembodiment is mounted coaxially upon the same shaft. The assembly has astable center-rest position due to the pre-stressing action of spring 9holding the yoke against a fixed stop means or stop-screw 8, and thepre-stressing action of spring 7 holding the lever against the anvilpoint 6 on the yoke. The contact screws 11 and 14 are adjusted so thatthe lever is positioned midway between these contacts, but not touching.When pressure is applied to handle 16 toward the left, the lever 4 movestoward the left against the spring 7, and contact is made between 13 and13', without any movement of the yoke 5, but the levelwhen in thisposition leaves the anvil point 6 on the rockerarm. When pressure isreleased on the handle, the lever returns to its original center-restposition due to the action of spring 7. When pressure is applied to thehandle 16 toward the right, the lever 4 moves toward the right,simultaneously shifting with it the yoke 5, against the action of spring9, closing contacts 10 and 10', but the yoke while in this positionleaves the stop-screw 8. When the pressure is released on the handle,the assembly of lever and yoke returns to its original center-restposition due to the action of spring 9.

The lever 4 has a firm center point of rest by virtue of thepre-stressing of springs 7 and'-9. Thus, to move the lever either rightor left from its rest position requires appreciable finger pressure, sothat the lever is held at rest against transient forces.

When the lever 4 is moved to either the right or left, to make contactwith the rigid stationary contacts, there is a tendency for the lever tochatter or bounce against the contact, causing contact bounce. Thefrequency of this 3 detrimental bounce or chatter appears to be afunction of lever mass and its moment arm, spring tension, and the sidepressure against the handle; Due to the very minute currents (usuallymeasured in rnicro-amperes) handled by the contacts when controlling anelectronic keyer, this contact bounce often causes erratic keying. Thiscondition becomes particularly aggravated as the contacts becomeoxidized or dirty. To remedy this condition, the handles 16 and '16 aredesigned to have .a certain amount of flexibility. In accordance withthis invention, it has been found that when the handles compriseapproximately /3 the length of the total moving arm, their flexibilityserves to dampen the detrimental chattering, thereby very effectivelyeliminating the problems of contact bounce, and giving a smooth, uniformkeying action. For any given set of handles, the amount of flexibilityrequired to give the desired damping action is dependent upon thestiffness to which the springs 7 and 9 are adjusted. For the usualstiffness to which these springs are adjusted for normal operation, thehandles should deflect between .001 and .010 inch, when side pressure isapplied near their outer extremity to move the lever to make contact toeither the right or left of the center-rest position.

The base 1 is made preferably of metal with a weight of about threepounds to give the desired stability, to prevent walking or sidemovement during operation of the key. An excess of weight, however, isdetrimental as it interferes with the portability of the key, and alsoincreases shipping charges and the manufacturing costs. It thereiore isvery desirous to have the weight of the base positioned or placed at themost advantageous position. Since the side-thrusts to move the lever areapplied at 16 or 16', the base tends to rotate about the foot 2', andthe turning moment is the product of the side-thrust multiplied by thelength of the moment arm 16-2' or 16 To resist this turning moment andobtain the desired stability, there exists the downward pressure exertedagainst the feet 2 and 2" multiplied by the coeflicient of friction,which product is then multiplied by the moment arm or distance between 2(or 2") and the pivot foot at 2'. It will therefore be seen that it isdesirable to concentrate all possible weight as far forward as possible;i.e., away from the pivot foot 2'. Tests have shown that at least 65percent of the weight of the base should be concentrated forward of themid-point, 17 of the lever 4.

An eminently satisfactory key mechanism is being marketed embodying thepresent invention and having the following parameters: Length of keylever from pivot 3 to end of handles 16, 4% inches. Distance from pivot3 to center of rear foot 2', /2". Weight of base 1, 3 pounds. Typicaloperating compression in bias springs (adjustable by screws): spring 7,3 ounces; spring 9, 4 ounces. Pressure to move lever to either right orleft, is one ounce. Typical adjustment between contacts 10, 10' and 13,13' (adjustable) .006 inch. All parts are metal, except the paddles 16which are Cycolac or Tenite plastic, having dimensions of about .100inch thick, one inch wide, and two inches in length, overall.

Although there has been shown and described herein a preferredembodiment of the invention, it is to be understood that this inventionwill not be limited to this particular description, and that changes maybe made in the materials, and in the structure and arrangement of theparts, within the spirit of this invention and the scope of the appendedclaims.

What is claimed is:

1. Manually operable electric key mechanism comprising a base, anelongate key lever pivoted one end to said base for oscillation about asubstantially vertical axis, a bifurcated yoke bracketing said lever andpivoted at its bight to said base coaxially with said lever, a springcompressed between said lever and one arm of said yoke and biasing saidlever into firm engagement with the other arm or said yoke, a stop onsaid base for limiting movement of said yoke, a spring compressedbetween said yoke and said base and biasing said yoke into said firmengagement with said stop, a first pair of spaced contacts mounted onsaid base and lever, respectively, and engageable by moving said leverin the opposite direction, said lever having at least one flat paddle onthe end thereof opposite said axis and made of material appreciably morei flexible than the remainder of said lever.

. pivoted and elongate and extending from the pivot axis in generallythe same direct-ion, said stop member comprising a member havingportions extending on both sides of said key member, said first biasingmeans comprising a spring compressed between said key member and oneside portion of said stop member, to bias said key member intoengagement with the other side portion of said stop member, said fixedstop means being fixed to said base on the same side of said key memberas said first biasing means, and said second biasing means comprising aspring compressed between said :base and said other side portion of saidstop member.

3. Manually operable electric key mechanism comprising; a base, amovably mounted key member, a movably mounted stop member, meansengaging said key and stop members for biasing said key member intoengagement with said stop member, fixed stop means for limiting movementof said stop member in a given direction, and means for biasing saidstop member into engagement with said stop means; said members beingcoaxially pivoted and elongate and extending irom the pivot axis ingenerally the same direction, said stop member comprising a bifurcatedyoke pivoted at its bight and bracketing said key member, said firstbiasing means comprising a spring compressed between said key member andone arm of said yoke to bias said key member into engagement with theother arm of said yoke, said fixed stop means being fixed to said base,and said second biasing means comprising a spring compressed betweensaid yoke and said base.

4. Manually operable electric key mechanism compmsing; a movably mountedkey member, a movably mounted stop member, means engaging said key andstop members for biasing said key member into engagement .With said stopmember, fixed stop means for limiting movement of said stop member in agiven direction, and means for biasing said stop member into engagementwith said stop means; said members being coaxially pivoted and elongateand extending from the pivot axis in gen enally the same direction, saidstop member comprising a member having portions extending on both sidesof said key member, said first biasing means comprising a springcompressed between said key member and one side portion of said stopmember, to bias said key member into engagement with the other sideportion of said stop member, said fixed stop means being fixed to saidbase on the same side of said key member as said first biasing means,and said second biasing means comprising a spring compressed betweensaid base and said other side portion of said stop member, there being acontact point on the said other side portion of said stop member.

5. Manually operable electric key mechanism comprising; a base, anelongate key lever pivoted at one end of said base for pivoting about asubstantially vertical axis, a first pair of contacts mountedrespectively on said lever and base and engageable by movement of saidlever in one direction, a second pair of contacts mounted respectivelyon said lever and base "and engageable by movement of said lever in theopposite direction, means References Cited in the file of this patentUNITED STATES PATENTS Martin Feb. 13, 1923 Martin Feb. 21, 1939Heatherly June 29, 1943

1. MANUALLY OPERABLE ELECTRIC KEY MECHANISM COMPRISING A BASE, ANELONGATE KEY LEVER PIVOTED ONE END TO SAID BASE FOR OSCILLATION ABOUT ASUBSTANTIALLY VERTICAL AXIS, A BIFURCATED YOKE BRACKETING SAID LEVER ANDPIVOTED AT ITS BIGHT TO SAID BASE COAXIALLY WITH SAID LEVER, A SPRINGCOMPRESSED BETWEEN SAID LEVER AND ONE ARM OF SAID YOKE AND BIASING SAIDLEVER INTO FIRM ENGAGEMENT WITH THE OTHER ARM OF SAID YOKE, A STOP ONSAID BASE FOR LIMITING MOVEMENT OF SAID YOKE, A SPRING COMPRESSEDBETWEEN SAID YOKE AND SAID BASE AND BIASING SAID YOKE INTO SAID FIRMENGAGEMENT WITH SAID STOP, A FIRST PAIR OF SPACED CONTACTS MOUNTED ONSAID BASE AND LEVER, RESPECTIVELY, AND ENGAGEABLE BY MOVING SAID LEVERIN THE OPPOSITE DIRECTION, SAID LEVER HAVING AT LEAST ONE FLAT PADDLE ONTHE END THEREOF OPPOSITE SAID AXIS AND MADE OF MATERIAL APPRECIABLY MOREFLEXIBLE THAN THE REMAINDER OF SAID LEVER.